The present invention relates to an automated inventory scanning system, including methods and devices utilizing novel aerial scanning antennae, robots, unmanned aerial vehicles, and RFID (radio-frequency identification) transponders.
Robots are disclosed for aerial scanning using either propellers to lift an unmanned aerial vehicle (UAV), or a scissor lift mounted to a two-wheeled robot for maneuvering an RFID antenna to vertical storage spaces that are located well above floor level.
Radio-frequency identification (RFID) transponders enable improved identification and tracking of objects by encoding data electronically in a compact tag or label. Radio-frequency identification (RFID) transponders, typically thin transceivers that include an integrated circuit chip having radio frequency circuits, control logic, memory and an antenna structure mounted on a supporting substrate, enable vast amounts of information to be encoded and stored and have unique identification.
RFID transponders rank into two primary categories: active (or battery assist) RFID transponders and passive RFID transponders. Active RFID transponders include an integrated power source capable of self-generating signals, which may be used by other, remote reading devices to interpret the data associated with the transponder. Active transponders include batteries and, historically, are considered considerably more expensive than passive RFID transponders. Passive RFID transponders backscatter incident RF energy to remote devices such as interrogators.
Reflections from shelving and other metal objects in the field of an RFID reader are can blind and possibly saturate baseband amplifiers preventing tag reading. Circularly polarized (CP) antennae have vector rotation noise that results in periodic polarization misalignments with linearly polarized RFID transponders at quarter wavelength intervals from the CP antenna. Aerial RFID scanning also introduces significant ground-bounce problems that also result in poor RFID transponder interrogation performance. These and other problems are overcome by the presently disclosed invention. No prior art comprehensively teaches systems, methods or devices for moving among, overcoming carrier reflections, nulls, and ground bounce to automatically determine the location of RFID-tagged inventory.